The best and worst – fuel consumption

Everyone knows that a supermini will drink less fuel than a supercar, but which of the pint-sized options is the most frugal at the pumps?

We'll take you through each of our car categories to find the best and worst in each class – for both petrol and diesel where appropriate. We'll also show you what the difference means in hard cash over 12,000 miles.

All of the comparisons are based on the official average mpg. It's not a perfect system - you're unlikely to get within 10% of the figure in the real world – but at least it's a relatively level playing field.

There's more to life than fuel costsDon't forget, though, there's more to the running costs of your car than fuel. Depreciation plays a massive roll in how cost-effective your car will prove to be over three years, so always remember to factor that in along with insurance, servicing and tax costs.

To help you with your sums we've produced a petrol versus diesel calculator into which you can punch the numbers to find out which car really will cost you less over three years and 36,000 miles.

The following prices relate to how much fuel will cost - and how much money can be saved - over a distance of 12,000 miles